Wildlife

Bourne Valley Wildlife

About the Stream:

from this page:

The Bourne Valley is renowned for its wildlife, with all six British reptile species to be found at the SSSI

See

Bourne Valley SSSI

for more about wildlife, including:

Breeding birds ~ Invertebrates ~ Dragonflies and Damselflies

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Cetti's Warbler

The rarely seen Cetti's Warbler (Cettia cetti) has made an unexpected visit to the new lagoons and wetlands at Alderney, but has only so far been heard! Will it nest here? We are keenly listening and watching and will bring news when we have it.

This is a Mediterranean species which has steadily spread through France and was first seen in England, Belgium, the Netherlands and Germany in the 1960s. It suffers during prolonged, severe winters and the population in Kent declined dramatically after the cold winters in 1984/5 and 1985/6.

A small brown, insect-eating bird, it is best located by its loud, explosive and far-reaching song which is usually given from deep within a bush or other scrubby vegetation, close to water. The Cetti's Warbler is unique among British songbirds-it has only ten tail feathers and it lays bright red eggs.

There have been other Dorset sightings in recent years at Radipole Lake and Lodmoor.

Source: http://www.notts-rspb.org.uk

» Read more about Cetti's Warbler

» Listen to the warbler's distinctive song - Source: Jeff Blincows Sound Gallery

A refuge for Water Voles

see a Water Vole

in its natural habitat

The Bourne Stream is a refuge for the Water Vole (Arvicola terrestris). This is a Biodiversity Action Plan priority species which means it is receiving priority action on a national level in order to reverse its rapid population decline over the last 10 years. The population crash has been brought about through habitat destruction and the spread of the American Mink throughout England.

The area around Alder Hills Road is particularly good for Water Voles who are dependent on long grass and in-channel vegetation for their survival. In 2005 there have been confirmed sightings at the new Bourne Pools, where the concrete channel has been removed and gentler slopes left to develop undisturbed bankside vegetation.

Water Voles are quite docile creatures who are out of their burrows both day and night, so if you sit by the river quietly you may hear a loud ‘plop’ as one dives into the water, or see one chomping its way through vegetation.

They are not to be mistaken for rats which are also present on the stream. Rats are a similar size to Water Voles but have large ears and pointy faces.

A ‘Know Your Vole’ identification card is available from Dorset Wildlife Trust to help distinguish between voles and rats.

» more information from the UK Biodiversity website

Beetling along the Bourne stream…

see a larger picture of Donacia bicolora

A rare iridescent green aquatic beetle Donacia bicolora was surveyed in 2001 and is still present on the Bourne Valley SSSI. The species has its own national Species Action Plan and is very rare across southern England. It lives on branched bur reed where its larvae live in the roots and the adults on the plants above water. There are only two tiny areas of the plant remaining in the stream.

In 2003 work was carried out by Borough of Poole Countryside Services to increase the bur reed (and its beetles!) in the valley. Funded by English Nature.

» more information from the UK Biodiversity website

Ruddy Darters

There are several species of dragonflies and damselflies to be found on and around the Bourne Stream. The reed pond at Alderney Recreation Ground has probably the strongest population of Ruddy Darters in the valley.

See the male of the species by enlarging the thumbnail above.

» Dragonfly facts

The Grey Wagtail (Motacilla cinerea) can be seen in Coy Pond Gardens, most noticeably since the improvements made to the stream there.

Summer habitat comprises fresh flowing water (river and streams) neighbouring woodland or scrub and waterside shingle or rocks. In winter they move out of upland areas to more lowland rivers and streams. They are badly effected by harsh winters, and because of recent moderate declines it is an Amber List species.

The White-Legged Damselfly (Platycnemis pennipes) was spotted and snapped by Bournemouth University student Robert Aquilina during his study of the created wetlands at Alderney, where it is breeding.

Quite rare nationally, though locally abundant on rivers and canals in southern England, this species seeks out a muddy substrate abundant in marginal vegetation, but is sensitive to pollution.

» Dragonfly facts

Learn about Dorset's butterflies from www.dorsetbutterflies.co.uk

ENDANGERED SPECIES

Sand Lizard Lacerta Agilis

Surviving colonies are mostly confined to heathland habitats within coniferous forests, dry heaths of south Dorset, with only a few populations remaining in heathlands of south-west Surrey and the Merseyside sand dunes and one long established, introduced colony in Scotland on the Isle of Coll.

more information from the UK Biodiversity website

Smooth Snake Coronella austriaca

The smooth snake is Britain’s rarest reptile, c.1000-3000 adults, with a currently known though very limited distribution confined to Dorset, Hampshire, Surrey and West Sussex (the latter following a reintroduction).

more information from the Herpetological Conservation Trust website

Both species are protected nationally under Schedule 2 of the Conservation Act 1994; they are also internationally protected under the Council of Europe's Convention on European Wildlife and Natural Habitats (the Bern Convention) of 1979 and under the European Union's Habitats and Species Directive of 1992.